This proposal requests $600,000 to purchase a CyTOF ICP-TOF-MS Model C5 mass cytometer with an automated 96 well plate reader and associated control computer made by DVS Sciences, Inc. The CyTOF is a new type of cytometer, which uses reagents labeled with metal ions instead of fluorescent dyes to detect different cellular constituents. Whereas practical flow cytometry techniques allow for only 10-12 simultaneous measurements, the CyTOF allows up to 100. The Investigators desiring to use this technology see great potential for advancement in personalized medicine as a more complete characterization of disease states and responses to various treatments is possible with the CyTOF compared to conventional flow cytometry. The CyTOF will be installed in the Stanford Shared FACS Facility, a Service Center in the School of Medicine that provides flow cytometry instruments and technical expertise to the Stanford and regional academic biotechnology research communities.